Number converter



Nov. 3, 1953 R. A. EDWARDS j l I l I I I I I I I I I I I I I I I l I l I I I I l I l l l I I l l l l' J lllllllllllll Il N -S Vv u W G. a P P D V7 mm .E w O @n 31 D d wxh umm e E A W VA. ,n a t. u| u l lll l www A I@ H i- I- kik b m mw l/ O y m Q f on .D V 5 n N l \m, v. Tn VH NIH ull Hullllmm -l |11 1mm lu m\ S R o III .l Ill.' ||||||l 'l' Il l .Il alllllhll E N |||l Il m w @he Nu u F IN @MK u uw r l l I l I I I l l I l l I I I l l l Il. wv N X Patented Nov. 3, 1953 2,657,856 NUMBER CONVERTER Robert A. Edwards, Schenectady, to General Electric Company,

New York N. Y., assignor a corporation of Application November 15, 1949, Serial No. 127,468 6 Claims. (Cl. 235-61) This invention relates to numbers converters and more particularly to an electric converter capable of converting numbers of one radix to equivalent numbers of a different radix or capable of converting a number to some other predetermined function of that number.

Such a device is particularly useful in calculations involving numbers of different radix, in automatic coding machines, and in automatic calculating machines.

It is an object of this invention to provide an economical, reliable numbers converter for converting a number to a predetermined function of that number.

It is another object of this invention to provide a simple reliable electric converter capable of automatically converting a number of one radix to an equivalent number of a different radix.

A further Object is to provide a conversion circuit capable of use with a parallel adder and an electric programmer to convert a number of one radix to its equivalent number in a different radix.

In general, tric converter my invention consists of an eleccomprising a programmer, a conversion circuit and a parallel adder electrically interconnected in a predetermined order to automatically convert a number of one radix to its equivalent number of a dierent radix.

For a complete understandingr of my invention, reference should be had to the following speciiication and the accompanying drawing in which similar elements are given the same character reference throughout the drawing.

In the drawing, Fig. 1 is a diagrammatic view of an electric converter illustrative of my invention and capable of automatically converting any two digit number of radix 10 to its equivalent number in radix 2.

To understand the mathematics upon which my electric converter is based, assume, for example, that it is desired to convert the decimal nurnber 64 to its equivalent binary form. Such conversion could be numerically accomplished by adding the binary equivalents of 4 and 60. This manipulation is shown below:

lent number in radix 2 in accordance with my invention, I provide an electric converter of which the electric converter I shown in Fig. 1 of the drawing, is illustrative. The electric converter l comprises a conventional electric programmer 2 having two outputs 3 and 4 corresponding to the two digits of the number to be converted, a conversion circuit 5 and a parallel adder 6 having a plurality of inputs l. The programmer 2 may be any conventional device having an input electrically connected to a grounded source of positive voltage (not shown) and arranged t0 produce in time sequence a voltage pulse on each of a plurality of outputs, such as 3 and 4. For example, a programmer may comprise a D. C. motor not shown) arranged to close a plurality of contacts (not shown) in time sequence for one revolution of the motor and by closing the contacts in sequence, exciting the outputs of the programmer in time sequence. The conversion circuit 5 comprises a switching means such as a keyboard 8, a buffer means 9, and a matrix I0. The keyboard 8 comprises a rst and second group of selectively operable switches numbered respectively II and I 2, the number of switches in each group of switches corresponding to the number of characters to be represented in each digit of the number to be converted. For example, the radix of the number to be converted by converter I being ten, the number of switches in each group of switches is ten. The iirst group of switches Il are arranged to represent by selective operation thereof the units digit of the number to be converted and are therefore numbered Uil-Uil, as shown in Fig. 1 of the drawing, corresponding to the decimals 0-9. In the same manner, the second group of switches IZ are numbered T-TS corresponding to the tens decimal characters 0-90.

The groups of switches II and I2 are provided respectively with input terminals I la and ld and output terminals II b and IZb. The input terminals I I a and I 2a cf the groups of switches II and I2 are electrically connected respectively to the outputs 4 and t* of the programmer 2 to be successively excited thereby in a particular order.

groups of switches II and l2 are electrically conmeans 9 to the matrix I il. Buffer means 9 comprises a plurality of neon tubes I3 and a plurality of associated resistance means I4. The neon tubes I3 and resistors I4 are selectively grouped to form associated groups of neon tubes and resistors numbered I-32 and electrically connected to the groups of switches I I and I2 as shown in Fig, l. The reason for so grouping the neon tubes and resistors will become evident in a description of the matrix I0 to follow. Each oi the neon tubes I3 is electrically connected through its associated resistor I4 to a particular :output `conductor of 'the matrix I0, the outputfconductorsbeing numbered SI ,"S2, S4, S8, SIG, S32, and S64 to indicate the decimal sums 1, 2, 4, 8, 16, 32 and 64.

Those skilled in the art Will understand that a parallel binary adder, an example Aof Awhich is disclosed in a publication 4=by .the `University -of Pennsylvania., Moore School of Electrical vlingi- :f

neering, titled Theory and Techniques for Design of Electronic Digital Computers, volume y3, Lecture 23, may have a plurality of inputs corresponding to the decimals 1, 2, 4, 8, r'6,32, and 64 such that excitationfof particular inputs actuates 4,the ,parallel binary adder -tostore therein .the :.binary, equivalent of .the .sum :of the decimals represented by the-input lines. rPhus output con- ,ductorsSI-rSM ofthe matrix yIE! are electrically ,connected to the inputs lI `of the parallel adder 6 inapredetermined .order to store lin the adder `the binary equivalent of the decimal number corresponding .to the ,particular output conductorsSI-Sllenergized -l-or example, vwhen out- -putfconductor S64 .iszenergized the binaryrequiv- .alent `of the decimal 64 is stored in the binary .adder-6,.and-when output conductor S32 .is fenerlgized `the binary equivalent of the zdecimal 32 is stored in-the adderf.

'I-o .follow the operation .of the .Converter I as above lrdescribed, assume, Afor example, that it is -`desired -to convert the `decimal F13 to its equivalent -in binary notation, .1n this operation switch U3 :and .switch '.1110 are -closed :to electrically conlnect the programmer :2 through its voutputs 3 l and 4 to thegroups of1neontubes-2| and 26. r-For .convenience of description, 1I=have :numbered -the tubes in group 2.I as 3335 and the `tubes in group y26 as 33 :and.3-1. Thereafter, operation of `the programmer 2 is initiated yby closing an loperationlswitch (not shown) of .the rprogrammer tto supply .the programmer with [electric power .through Ithe input X and outputs 3 and 4 are thereby energized in Ya particular `order Vdepending lupon the arrangement of the programmer. .The reason .for programing `the energization 4oi lines 3 land `4 is 4to allow Vsufficient time for the `.parallel adder 'to accumulate the information supplied by -the energization of one output `of the ,programmer before lthe -other -output is ener- .gized .Assume that the .output 4 .-is energized first. In this event, Vneon .tubes .36 .and 31 .are impressed bythe programmer with `a voltage Ain the order of 100 volts. 'The characteristic of neon tubes is such that the tube will not .ionize `until a voltage .of 7.0 volts is .applied to .the input o'f the Itube.`Until 7.0 volts :is `applied thereto the tube acts for practical ,purposes of .this .inven- A'tion as an insulator. After 70 volts is applied,

the neon 'tube ionizes and thereby ypresents a finite impedance in an electric .circuit regardless of vadditional voltage applied thereto .and main `tains a iinite constant voltage .of .substantially '50 volts .across its terminals. Thus, .the Voltage output of tubes 36 .an 31 is the difference `of 100 volts applied to the neon .tube and .the -50 volts potential vdrop through the tube.

The outputs of .50 volts leach from the tubes 36 and 31 .are applied respectively .to the matrixoutput conductors .SI .and S2 each through the L.assoreceived from 1S-I and S2, fexcites output line 3 which through the medium .radix l10 -may be converted by ciated resistors I4 connected to the tubes 36 and 31. Although some voltage drop occurs through the resistors I4, the amount of drop is negligible and therefore substantially 50 volts is applied to the matrix conductors SI and S2 to actuate the parallel adder 6 and store therein the binary equivalent of the decimal 3. That is, the adder i6 stores the binary equivalent of the decimal 1 .in response to `50 volts applied to matrix conductor SI and further adds the equivalent of the :decimal 2 upon application of 50 volts to the .matrix .conductor S2, After a sufficient time has elapsed for the adder to store the information the programmer then of closed switch VT10 applies 100 volts to the group of neon tubes 2I thereby applying 50 volts 'to matrix conductors S64, S4, and S2. The volt- ,agexthus applied to S54, S4 and S2 operates the adder 6 to add the binary equivalents of decimals .64, Aland 2 tothe binary equivalent-of 2 I.plus 1 already stored .therein to -produce the binary equivalent of the.decimal"13. .Infa similar manner by closing particular `ones )of the switches UD-US and "f6-T33 and thereater operating the programmer r2 `any two digit number lof converter `I to its equivalent binary number. Portions of the circuit (not shown) of the -binary adder .6 are grounded to return current supplied vto lthe binary adder `'r3 from the programmer `2 back to the .grounded power source from .which :input .X of

the programmer -2 vis energized.

To provide for the conversion of radix 110 numbers having -more than two-digits, itis necessary to add an `additional Vgroup-of switches for each ,digitincrease provide aprogrammer -with a corresponding number of outputs, and increase -the elements of buffer 9, matrix I0 and paralleladder -6 -to correspond.

VA .particular advantage .in .the use of :neon tubes .as buffer elements vin .my inventionshould be vnoted ,at -this time. That is, the voltage drop of the neon tubes being substantially constant at 50 .volts and neon tubes .requiring at least 70 volts to ionize, -it is, therefore, impossible .for Aexcitation of one of the rmatrixnutput conductors tocausea leak-back through aineon tube Lto1an vother of the Vmatrix output `conductors and thereby cause a false-addition in the adder. .For yexamplaneon tube v when ionizedapplies only 50 volts to conductor S2 with `100 volts applied to the neon tubeinput. Conductor S2 is electrically `connected to conductor SI through the :neon tubes 36 and 31. However, neither tube x36 .nor `3.1 willoperateono volts and therefore conductor -S'I .cannot be energized trom conductor S2. .In .asimilar manner, leakage between any of the output conductors AS-I--S4 is .prevented :by lthe inherent characteristics of the neon tubes.

The neon tubes I3 mayconsist -merelyof small, inexpensive neon `glow lamps whichlare'commonly 'used ras .indicator lamps. This is .possible because, .in the operation of the lconverter of this invention the voltage characteristics of Athese neon tubes are not critical. That is, -it -is not absolutely necessary that conduction begin at exactly l'10 volts nor that the normal voltage drop across each conductive tube should "-be exactly volts. The primary purpose of the vglow tubes or glow lamps I3 is to prevent 'false operation of the numbers converter by unintended'energization of out- .put'oircuits which are necessarily interconnected :through unenergized input circuits. For instance, referring back `to Vthe above example, 'in

order for output conductor Sl through energ1zat1on of output conductor S2 from tube 35,

ated in the series combination of tubes 35, 3S and 31.

ratus is designed with only approximately 100 input volts available. The practical limit of tolerance on the voltage for which the glow tubes or lamps are capable of initiating conduction may therefore go from the nominal 70 volts to as low as 33 volts before false operation of the apparatus is likely to occur.

Thus in accordance with my invention, I provide a simple inexpensive electric converter for converting a number of one radix to its equivalent number in a different radix.

Moreover, by applying neon tubes in my converter, as indicated, a simple inexpensive means is provided for buifering each matrix conductor from other matrix conductors electrically connected to the same buffer group thereby preventing false indications in the parallel adder and insuring reliable operation thereof.

My invention as above described is particularly useful as an incorporated portion of a high machine and may also be used If desired, the manually operated keyboard arrangement above described may be replaced by relay operated switches responsive to voltage signals received from a conventional voltage signal producing machine activated in response to a punched tape or card supplying thereto the number information to be converted.

While I have shown and described particular my invention, it will be obvious in the art that various changes and modifications may be made without departing from my invention in its broader aspects and I, therefore, aim in the broader claims to cover all such changes and modications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. An electric device for converting a number of one radix to its equivalent number of a different radix comprising an electric programmer,

a switch means having output terminals electrically connected thereby to said programmer in a predetermined order to be energized thereby, a parallel electric adder, an electric matrix having output conductors electrically connected to said parallel adder in a predetermined order and also having input conductors more than one of which are connected to the same output conductor and means for connecting a predetermined number of said input conductors to different output terminals of said switch means, said means including a plurality of electric buffer means each having in each direction therethrough a nonlinear voltage-current characteristic providing for no conduction below a predetermined substantial impressed voltage and for a limited voltage drop relatively independent of impressed voltage during conduction, a single and different one of said electric buffer means being connected in circuit with each of said input conductors to an output terminal of said switch means.

2. An electric device for converting a number of one radix to its equivalent number of a different radix comprising an electric programmer, a switch means electricallyconnected to said predetermined order to be energized thereby, a parallel electric adder, an electric matrix electrically connected to said parallel adder 1n a predetermined order, and electric buffer means comprising neon tubes and associated resistors electrically connected in a predetermined relation between said matrix and said switch means.

3. An electric device for converting a given number of one radix to its equivalent number of a different radix comprising an electric programmer adapted to successively energize in time sequence a plurality of output conductors thereof corresponding in number to the number of digits of said given number, switch means comprogrammer in a ciated switch members, the number of said groups corresponding to the number of digits in said given number and the number of said switch members in each group being dependent upon the radix of said given number, an input and an output terminal for each switch member, connections for electrically connecting said input terminals of each group of bers to a particular one of said output conductors of said programmer to successively energize each group of associated switch members in response to operation of said programmer, an electric matrix having a plurality of input conductors and a plurality of output conductors electrically interconnected in a predetermined relation depending upon the radix and number of digits of said given number and the radix of said equivathereto through said buffer means, and a parallel adder having a plurality of input conductors each electrically connected to an associated output conductor of said matrix.

4. An electric device for converting a given number of one radix to its equivalent number of a diiferent radix comprising an electric programmer having a plurality of ouput conductors corresponding in number to the number of digits of said given number, said programmer being arranged to energize its output conductors in time connected to a particular o ne of said output conductors of said programmer, the number of switches in each group being dependent upon the radix of given number, a plurality of selected groups of buffer means each group comprising one or more neon tubes group of buffer means being electrically connected between a particular one of said switches and a particular set of said output conductors of said matrix to provide an electric buifer means between the output conductors of each set of conductors of said matrix while electrically connect- 'I ing said sets of output, conductors each toy a particular one.` of saidi output conductors of' said programmer; whereby upon selected opera-tion'- of grammer, andv aI parallel adder electrically connected to said output conductors of said matrix in a predetermined relation to be actuated thereby. in4 response tol thepredetermined voltages impressed on said output conductors of` said matrix toiproduceI said equivalent number in said different radix.

5f.v An electricdevice for converting a iirstnumber ofV one radix toits equivalent number of. a different radix comprising an electric programmer arranged to energize in sequence a plurality of outputconductors thereof corresponding in number to-the number off digits of said first number, an electric matrix having a plurality of output conductors dependent upon the radix ofV said first number and said equivalent number and the number of' digits of said first number, aplurality of groups of selectively operable electric switches, each of said: groups of switches comprising a number of switches corresponding to the number of' possible characters ofv each digit of said rst number, an input andan output vterminal on each switch, connections for connecting said input terminals of each group of switches to an associated one of said output conductors of said programmer, a plurality of groups of buffer means eachinits group electrically connecting to the output terminal, of. a particular one of said switches the particular. output conductors of a group of said output conductors of said matrix having at least one: output conductor common to `another groupthereof to cause said particular output conductors of said group tobeA supplied with. a.4 predetermined voltage from: said` programmer upon selected operation of said switches while'at'the-same time electrically buffering said output conductors of different groups thereof from the output conductors of the selected group, and a parallel adder electrically connected to said output conductorsv of said matrix in a predetermined relation, toA be actuated in responsev to operation of said programmer and selected op.- eration oisaidswitches'to indicate saidequivalent number in said diierent radix.

6; AnV electr-ic device for converting a: iirst number. of one radixto its equivalent number of f' a diiferent'radix comprising an electric programiner arranged to energize in sequence a plurality of output: conductors thereofl correspondingI in number to the number or digits of'. said firstnumber, an electric matrixhaving a plurality of output conductors dependent upon the radix of said iirst number and said equivalent number and the number of digits of said rst number, a plurality of` groups of selectively operable electric switches, each of said groups of switches comprising a number of switches corresponding to the number of possible characters of each digit of saldi first number, an input and an output terminal' for each switch, connections for connecting said" input terminals of each group of' switches to an` associated one of said output conductors of said programmer, a plurality of selected groups of neon tubes and associated resistors, each group being electrically connected to the output terminal of a particular one of said switches and to particular output conductors of said matrix ton cause said particular output conductors to be supplied with a predetermined voltage from said programmer upon selected operation ofsaid switches while at the same time electrically buffering said output conductors one from the other, and a parallel adder electrically connected' tosaid' out'- put conductors of said matrix ina predetermined relation to be actuated' in response to opera-tion of said programmer and selected operation of said switches to indicatesaidequivalent number in said different radix;

ROBERT A'. EDW'RDS.

Rectifier Networks for Multiposition Switching, Brown et al., Proc. I. R. E., Vol. 37, No. 2, Feb. 1949, pp. 139-147. 

